Circuits for telephone repeating systems.



-c. ADAMS-RANDALL.

CIRCUITS. FOB, TELEPHONE BEPEATING SYSTEMS. nruoumn FILED Jam, 1911.

1 ,0Q8,882. I Patented Nov. 14,- 1911.

- Mum... i* a UNITED srnras PATENT orrioE,

CHARLES ADAMS-RANDALL, OF NEW YORK, N. Y., ASSIGNOR TO RANDALL TELEPHONE MANUFACTURING COMPANY, OF AUGUSTA, MAINE, A CORPORATION OF MAINE.

CIRCUITS FOR TELEPHONE REPEATING SYSTEMS.

Specification of Letters Patent. Patented NOV. 14:, 1911.

Application filed January 3, 1911. Serial No. 600,648. 4 7

To all whom it may concern;;

Be it lmown that 1, CHARLES ADAMS-RAN- DALL, a citizen of the United States, residing at' New York city, in the county of New York and State of New York, have invented certain new and useful Improvements 1n Circuits for Telephone Repeating Systems; and I do hereby. declare the following tobe a full, clear, and exact description of the invention, such as will enable others skilled in the art .to which it appertains to make; and use-the same.

This invention relates to telephone repeating systems, and has for-its object to produce a system of this nature involving independent main line sending and receiving circuits adapted to repeat one into the other, and involving a relay or controller connected from one side of one of the main lines to the ground, all as will be more fully hereinafter disclosed and particularly polnt- When the parts are in the position shown v in the drawing, current may flow from the ground 14 over the connection 15 throughthe coils of the relay'16, and connection 17 back to the battery 6. The passage of current throughsaid coils of relay 16 will cause the armature 18 of said relay to be attracted, and the circuit to be closed at the contact 19. Current now flows from the local battery 20 over the connection 21 through the armature 18, contact 19, local wire 22 through the coils of the controller 23, connection 24 and over the connection. 25 back to the local battery 20. The passage of current through the coils of the controller 23 causes the latter to attract its armature 26 and to close circuit at the contacts 27,28

and 29. A person at an eastern'station E now wishing to commumcate with a western and wire 35 into the condenser 36.

secondary 33 of said coil which may be con-- sidered as leaving one end of said coil 33 over the connection 34 and passing through the connection 10, contact 5, lever 3, connection 2, lever 1, contact 9, main line wire 8, The passage of currents into the condenser 36 Wlll cause similar currents to flow out of.

said condenser along the mainline sending circuit 37 through the coils of the repeater 38 over the main line-sending circuit wire 39, the armature 26, the contact 28, main line wire 40, receiver 41, wire 42, and back to the other end of said coil 33. The passage of currents through the coils of the repeater 38 will cause said repeatento vary the resistance over its contacts 43 and 44, which will cause variable currents to flow from the local battery 45 over the local connection 46, through said contacts 43 and 44, over the connection 4r, primary coil 48, of the indu'ction coil 49, local connection 50, contact 29 and local connection 51, back to said battery 45. The passage of varying currents similar to the original currents generated at the transmitter 30 over the primary 48 of the said coil 49 will cause similar currents to be induced in the secondary 52 of said coil 49, and these currents may be supposed to leave one end of said coil 52 over the western main line receiving circuit 53, wire '54, wire'55'and into the condenser 56. The passage'of currents into the condenser 56 will cause similar currents to flow out of 95 nection 66, and backto the other end of'said secondary coil 52. The passage of these induced currents through the western receiver 64 similar to the voice-caused currents originally sent out from the transmitter 30 will reproduce the words at the western station which were spoken at the eastern station.

. When it is 'desired to talk from the west *ern station to the eastern station, the push a which permlts varylng currents toflow from 9, lever 1, connection 2, lever 3, contact 72,

,ceiver41, connection 111, contact 79, con

9 1910, Serial N 0. 598,345, entitled Telephone repeating systems connected by a single rem lay, but t e present application involves the r following diii'erence over said co-pending applicatlonz-ln the present application i'n'- stead of having the relay or a controller in a complete main line circuit, it is connected 18, said contact 74, the local wire 75, the coils of the western controller 76, local wire 77, and local connection 25 back to the said battery 20. The passage of current through the coils of said controller 7 6 attracts itsarmature 78 and causes circuit to be made at the contacts 79, 80 and 81. The operator atthe western station 1V upon pressing in the push button 83, makes circuit atthe contact 84, and upon talking into the transmitter causes currents-from the battery 86 to traverse the-primary 87 of the induction coil 88 in the manner well known. The passage of currents through said primary 7induces currents in the secondary 89 of said coil 88, which may be considered as leaving one end 01f said coil 89 over the mainline through contact 9-, lever l, con- 3n By this arrangement, of circuits, 1t Wlll be fore the resistance of said circuit is reduced. Further, by locating the relay in the grounded circuit as disclosed so far as the effective action of said relay and the battery 6 are concerned it does not make any dif- 90 ference how many bridges or short circuitsare out of the grounded circuit, and there- 35 connections 8 and 40. By arranging the circuits as indicated however, detrimental ef-' is to say, as is well known, the calling apparatus, drops and receivers of telephone systems are frequently placed in bridges I across or between connections similar to the .main line wires '8 and 40, as indicated at 150 andwhen a relayor controller such as 16 is in a main line circuit such as disclosed in my co-pending application above, for exam' I ple, the most effective use of the battery curthrough the connection 102, primary 103, of the coil 104, local connection 105, contact 81, local connection 106, back to said battery 100. The passage of these varying currents is prevented, as these bridges-constitute short circuits, and thereby deflect more or less of the main current between terminal stations, or for example, between a terminal station and an intermediate station. In practice this loss of power is obviated by including a-condenserin the bridged circuits,but' these condensers themselves are objectionable for well known reasons. lVIy arrange- 1'15 ment of circuits, however, obviates said oh jections, and enables me to employ as many" bridges without condensers as desired berents pass out of said condenser over the tween portions of the same'maln llne circult main-line 35, main line-connection 8, contact and into he condenser 109 s mil rt is obvious thatthose skilled in the art may vary the arrangement of circuits withnection 112 and backto the other end of said "ited to that Shown exceptas y be required 2,

coil 107. The passageofthese currents simiy the i lar to the original voice-caused currents W t I l m is: .7 through the eastern receiver 41 of course rer- In a telephone system e combmat'lon produces the speech originally uttered at-the f a main line sending circuit, an p western station I ent main line receiving circuit; means for-.130

as is apparent from the drawings. 12 0 V repeating an impedance,-

. fcuit,

repeating from oneof said circuits into the other; an electro magnetic device governing one of said circuits connected on one side to a impedance side to said partthrough a switch and an impedance; and a bridgebetween said part and another portion of said mainline cirsubstantially as described.

3. In a telephone system the combination of independent main line sending and receiving circuits; repeaters-and local circuits associated, with Copies 0! this patent may be. obtained for from one of said circuitsinto the part of oneof said circuits through an. and a battery, and on the other said main-line circuits, and

five cents eaoh, by addressing the Washington, D. 0.

an electro-magnetic device governing said circuits connected on one side through an impedance to -a part of one of said circuits, and also connected onthe other side to said part through an impedance, substantially as described 4. In a telephone of independent main line sending and receiv- 'ing circuits; repeaters and local circuits associated with said main. line circuits; an electro-magnetic device governing said circuits connected on one side through an im-v pedance to a part of one of said circuits; and also connected on the other side to said part through an impedance; and a bridge joining said part with another part of the same circuit, substantially as described.

In testimony whereof, I- afiix my signature, in presence of two witnesses.

HARLES ADAMS-RANDALL. Witnesses: I

Fnnonmcn B. BLAOKMAN, J OHN J. CARROLL.

Commissioner 0! Patents,

system the combination.- 

